package com.example.demo.configuration.filter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;

/**
 * 解决json跨域的过滤器
 *
 * @author Think
 */
@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCORSFilter implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest request = (HttpServletRequest) req;
        response.setHeader( "Access-Control-Allow-Origin", "*" );
        response.setHeader( "Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE" );
        response.setHeader( "Access-Control-Max-Age", "3600" );
        response.setHeader( "Access-Control-Allow-Credentials", "true" );
        response.setHeader( "Access-Control-Allow-Headers", "Origin,Accept,X-Requested-With,Content-Type,Access-Control-Request-Method,Access-Control-Request-Headers,Authorization" );
        if (request.getMethod().equals( HttpMethod.OPTIONS.name() )) {
            response.setStatus( HttpStatus.NO_CONTENT.value() );
        } else {
            chain.doFilter( req, res );
        }
    }

    @Override
    public void init(FilterConfig filterConfig) {
    }

    @Override
    public void destroy() {
    }
}
